package com.code.day18;

import java.util.Arrays;
import java.util.HashSet;

public class Demo15Hash {
    public static void main(String[] args) {
        HashSet<Person> set = new HashSet<>();
        set.add(new Person("张三", 18));

        String str = "abc";
        System.out.println(Arrays.toString(str.getBytes()));
    }
}
